Large commercial wind turbines are prone to lightning strikes and, in this regard, it is a common practice to provide the turbine blades with lightning receptors spaced along the longitudinal length of the blade so as to capture and conduct the strikes to ground. The conventional configuration of these receptors, however, results in difficult, expensive, and time-consuming maintenance and diagnostic procedures that typically require a crane to externally access each receptor. The conventional configuration does not offer a means to verify the continuity of the receptors within a blade without accessing and testing each receptor individually. In addition, the effectiveness of the receptors depends on the integrity and reliability of a single conductive path along the blade. Failure (i.e., a break) of this path renders any upstream receptors essentially useless.
Efforts have been made to devise alternative lightning protection systems for wind turbine blades. For example, U.S. Patent Publication No. 2009/0129927 describes a system that avoids blade mounted receptors altogether by mounting radially extending lightning receptors to the rotor hub, with the receptors extending between the blades. This configuration, however, may result in increased weight, drag, and noise, and an overall decrease in the capability of the turbine.
Accordingly, the industry would benefit from an improved lightning protection system that utilizes blade-mounted receptors, yet avoids the disadvantages of conventional receptor configurations.